The PEM Concept and Initiative Performance Engineered Mixtures

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Performance Engineered MixturesTesting in Wisconsin

Performance Engineered MixturesTesting in Wisconsin

Kevin W. McMullen, P.E.President

Wisconsin Concrete Pavement Association

The PEM Concept and InitiativeThe PEM Concept and Initiative

• A partnership of agency and industry to

– Understand what makes concrete “good”– Specify the critical properties and test for them– Design the paving mixtures to meet those specifications

Performance Engineered MixturesPerformance Engineered Mixtures

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Performance Engineered Mixtures in WisconsinPerformance Engineered Mixtures in Wisconsin• More than a National priority, we have made it a state priority• FHWA Pooled Fund Study – WisDOT and WCPA are both

participating and funding.• Our Joint Concrete Pavement Technical Committee is in the lead

– We are getting beyond the decades old practice of blue book mixes, ACI 211 and tests of air, strength and slump.

– WisDOT and contractors are supporting the emphasis on durability and performance based specifications

• Wisconsin Highway Research Program project to verify what we are doing

PEM Research in WisconsinPEM Research in Wisconsin

• Evaluation of Current WI Mixes Using Performance Engineered Mixture Testing Protocols - Interim Report

• https://wisconsindot.gov/documents2/research/0092-17-07-interim-report.pdf

Aggregate Quality and Stability

OUR FIRST PRIORITY

Aggregate Quality and Stability

OUR FIRST PRIORITY

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Optimized Aggregate Gradation and Concrete Mixtures


• National Research• Tarantula Curve – Dr. Tyler Ley, OSU• Promoted by NCPTC• WisDOT and WCPA jointly developed the Standard

special provisions (STSP) and specifications for WisDOTwork

• Used on some construction projects in 2017 and has been incorporated into all concrete pavement projects by STSP since 2018.



• The GOALS– Stronger– More durable– Less permeable more dense concrete– Easier consolidated/workability– Improved ride

The TARANTULA curve!!!! Optimized Aggregate Gradation SpecOptimized Aggregate Gradation SpecTABLE 1 TARANTULA CURVE GRADATION BAND

SIEVE SIZES PERCENT RETAINED 2 in. 0 1 1/2 in. ≤5 1 in. <16 3/4 in. <20 1/2 in. 4-20 3/8 in. 4-20 No. 4 4-20 No. 8[1] <12 No. 16[1] <12 No. 30[1] [2] 4-20 No. 50 [2] 4-20 No. 100 [2] ≤10 No. 200 [2] ≤2.3

[1] Minimum of 15% retained on the sum of the #8, #16, and #30 sieves. [2] Conform to 24-34% retained of fine sand on the #30-200 sieves

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Optimized Aggregate Gradation SpecOptimized Aggregate Gradation SpecTABLE 2 JMF WORKING RANGE

SIEVE SIZES WORKING RANGE[1] (PERCENT)

2 in. ±5 1 1/2 in. ±5 1 in. ±5 3/4 in. ±5 1/2 in. ±5 3/8 in. ±5 No. 4 ±5 No. 8 ±4 No. 16 ±4 No. 30 ±4 No. 50 ±3 No. 100 ±2 No. 200 ≤ 2.3

[1] Working range limits of composite gradation based on moving average of 4 tests.

WisDOT Optimized Aggregate Gradation and Mixture Design STSP


PART 1• Defines optimized gradation• Outlines spec and testing requirements• Contractor eligible for 3% incentive• Sample on the belt leading to the weigh hopper• Or, working face of the stockpile• Test each component aggregate once per 1,500 CY of

concrete production• Moving average of four tests

What does the research project say?What does the research project say?

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PART 2• Once aggregate gradation is optimized contractor can

elect to go to mixture optimization• Can reduce cementitious content to 520 lbs/CY.• Utilizes new national design procedure• Up to 30% replacement with fly ash, slag or combination• Need to include the departments Flexural Strength for Mix

Design STSP or the Concrete Pavement Flexural Strength SPV



1. Utilizes mix design procedure and spreadsheet developed by the National Concrete Pavement Technology Center

2. Utilize the spreadsheet to obtain an aggregate gradation system that fits within the Tarantula Curve and is relatively close to the power 45 curve.

3. Determine the volume of voids in the selected aggregate gradation system.a) Run ASTM C29 Specific Gravity on the proposed proportions of each aggregate.

4. Select the paste parameters; binder type, percentages, air content, w/cm.5. Select an Initial Vpaste / Vvoids value (1.25 – 2.00).



6. Calculate the paste content utilizing the spreadsheet. WisDOT requires a minimum cement content of 520 lbs so the Vpaste / Vvoids value may need to be adjusted to meet this minimum cement content

7. Prepare trial batches and assess fresh properties and workability.8. Prepare final trial batch and assess hardened properties.

BOX TEST

WorkabilityWorkability

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Assess WorkabilityAssess Workability

• Box Test• V Kelly Ball

BOX TESTBOX TEST

BOX TESTBOX TEST

From the research project

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V-KELLYV-KELLY ASR TestingASR Testing

• First time incorporated into the standard specifications

501.2.5.4.4 Alkali Silica Reactivity Testing and Mitigation Requirements (1) If using coarse aggregate from sources containing significant amounts of fine-grained granitic rocks including felsic-volcanics, felsic-metavolcanics, rhyolite, diorite, gneiss, or quartzite; test coarse aggregate according to ASTM C1260 for alkali silica reactivity. Gravel aggregates are exempt from this requirement. (2) If ASTM C1260 tests indicate a 14-day expansion of 0.15 percent or greater, perform additional testing according to ASTM C1567. Test mortar bars made with coarse aggregate and the blend of cementitious materials proposed for concrete placed under the contract. The department will reject the aggregate if ASTM C1567 tests confirm mortar bar expansion of 0.15 percent or greater at 14 days.



• WisDOT Spreadsheet• Originally developed at National Center for Concrete

Pavement Technology• Adapted for WisDOT use• STSP requires use and submittal of this spreadsheet for

approval• http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-

rsrces/qmp/default.aspx

New Aggregate System

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New Data Charts New Paste Quality

New Mix Design (Solver)

STRENGTHSTRENGTH

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Flexural StrengthFlexural Strength

• WisDOT basis for design is flexural strength in AASHTO pavement design procedure.

• Makes sense to assure we are achieving what was designed for

Special Provision Flexural StrengthSpecial Provision Flexural StrengthMaximum resistance of a concrete specimen to bending.• 6-inch x 6-inch x 21-inch

concrete beams• Third-point loading in

accordance with AASHTO T 97.


• Two SPV’s– SPV for mix qualification– SPV for strength acceptance

• Incentive/disincentive pay model for flexural strength is based on data from pilot projects over the last decade


• http://wisconsindot.gov/Pages/doing-bus/eng-consultants/cnslt-rsrces/qmp/default.aspx

• Requires design of a mix using flexural strength• Replaces all 28-day compressive strengths with flexural

strengths• New pay equations

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Flexural Strength ChallengesFlexural Strength Challenges

• Molds• Equipment – breakers• Curing facilities to assure QC and QV are cured equally• Sensitivity of flexural beams• Risk Management (beam and mold can weigh as much as

110 pounds)

Flexural Strength Moving ForwardFlexural Strength Moving Forward

• Limited use• Interstate/freeway only type projects• Greater than 20,000 square yards• Coordination with central office

From the research project:From the research project:

FREEZE THAW RESISTANCEFREEZE THAW RESISTANCE

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SUPER AIR METER (SAM)SUPER AIR METER (SAM) SAM Moving ForwardSAM Moving Forward• Incorporated into specifications in December 2017• Requires doing SAM during Mix Design (715.2.3.1)• Requires SAM test once per lot during concrete paving

(715.3.1.1)• Shadow specification to begin building database of where

WI mixes are• Does not impact acceptance• Timeline to move to acceptance in 2021?• WisDOT moving to structure specifications. Shadow

testing begins in 2020

2021 SAM spec?

• 2 years of shadow specification• 587 data points• 72.7% </= 0.2• 19.4% >0.2 and </=0.25• 2.9% >0.25 and </=0.3• 4.9% >0.3

From the research project:

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TRANSPORT PROPERTIES(the next priority)

TRANSPORT PROPERTIES(the next priority)

Electric ResistivityElectric Resistivity

• Durability measurement• Correlates very well with

Rapid Chloride Permeability.

• RPC 28-day test• This can be used on any

cylinder or concrete.

Formation FactorFormation Factor• Resistivity

– Store a cylinder in a fixed salt solution– Pull out at desired age– Read and put back– Repeat– Calculate formation factor (x10)

• F = Resistivity (bulk)Resistivity (solution)

From the research project:From the research project:

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After that?After that?

• Resistance to deicing salt attack? – Calcium Oxychloride test – SCM use

• Shrinkage (the last piece of the puzzle)– Is this impacting pavement performance?

ShrinkageShrinkage• Paste content (read the batch sheet)

– Easy– Fast

Project Gravel 1" 5/15/2017

Mixture ProportionsTargets Actual

Pounds R.D. VolumeCement Type I 342 3.15 1.74SCM 1 F Ash 86 2.65 0.52SCM 2 Slag 0 1.00 0.00Coarse Agg A85006 1753 2.72 10.33Fine Agg A25518 1318 2.66 7.94Intermediate A85007 340 2.43 2.24Water 180 1.00 2.88Air % 5.0 1.35

4019 27.00

Cementitious 428 428 pcyVolume of paste 24.0 %Volume of aggs 76.0 %Volume of voids 19.2vp/vv 125 125.0w/cm 0.42 0.42% SCM 1 20 20 %% SCM 2 0 0 %Mass aggs 3411 3411 pcyExcess paste, % 4.8 %

Shrinkage Discussion To Date With WisDOTShrinkage Discussion To Date With WisDOT

• Pavements– Low priority– Short joint spacing– Early cracking not a performance problem/concern

• Structures– Higher priority– Reduction in bridge deck cracking is a high priority

QUESTIONS?QUESTIONS?Kevin W. McMullen, P.E.

PresidentWisconsin Concrete Pavement Association

4001 Nakoosa Trail, Suite 101Madison, WI 53714

Email: [email protected]: (608)240-1020Mobil: (608)209-0878

Documents

The PEM Concept and Initiative Performance Engineered Mixtures